It is with incredible sadness that we announce the passing of Stephen S. Shatz. Steve married Marilyn (nee Karpman) in December 1958. While married (divorced in 1977), they had two children, both of whom survive him – Geoffrey Shatz (married to Kristin) of Philadelphia and Aviva (fka Adria) Shatz of Fayetteville, AR. He is also survived by three grandchildren – Richard Gutierrez, Max Gutierrez, and Zane Wood.

An emeritus professor of mathematics, Steve died in July in Philadelphia, age 86. His passions and interests took in the full range of the sciences and arts. He was an avid eater who possessed advanced cooking skills and an expert knowledge of wine; he shared his love of astronomy with his friends and family; he found beauty in classical music – patronizing the Philadelphia Chamber Music Society and playing the flute – and loved learning to speak or read multiple languages, including but not limited to Italian, French, German, Russian and Yiddish; he even created his own translation of Dante’s ‘La Divina Comedia’.

Steve was known as a story-teller recounting adventures from his full life. From his Harvard years, he recounted when he drove hundreds of miles to a physics conference as an undergraduate with to-be Nobel prize winner Julian Schwinger and when he auditioned for and was accepted in a music performance class taught by Leonard Bernstein; from his travels as a mathematician, when a pesky rabbit almost foiled a lesson for his children about not eating poisonous mushrooms outside of Pisa, IT. 

His life was nearly cut short in the early 1970s when he was diagnosed with cancer, likely stemming from an accident with a chemistry set in the 1950s. After five operations, the amputation of his right forearm, and chemotherapy, the cancer went into remission. 

Born April 27, 1937, in Brooklyn, Steve attended P.S. 103 and then Montauk Junior High School before heading to Stuyvesant High School, the New York City honors high school. His parents were Nathan Shatz, an accountant, and Gussie Shatz, an opera singer and then homemaker. She would sing with Steve and his older brother Malcolm, imparting to them a love of opera.

Steve Shatz started at Harvard University in 1953, age 16, and earned an undergraduate degree in physics and then a Ph.D. in mathematics with a dissertation on The Cohomology of Artinian Group Schemes Over Local Fields under the direction of Professor John Torrence Tate Jr. Following the award of his Ph.D., in 1962, Steve was an instructor and then acting assistant professor at Stanford University through 1964. He then joined the faculty of the University of Pennsylvania, where he rose from assistant to associate to full professor from 1964 through 2005 before retiring on January 1, 2006. During that period, he chaired the Penn mathematics department from 1983 to 1986. Following retirement, Steve continued to conduct mathematical research and teach. During this period he developed a collaboration with Jean Gallier of  the University of Pennsylvania Department of Computer and Information Science, producing manuscripts on algebra, algebraic geometry, and complex algebraic geometry.

His early papers in number theory broke ground in the investigation of cohomologies of sheaves for the flat topology of schemes invented by Grothendieck around 1960.  In his Ph.D. dissertation published in the Annals of Math., he generalized Tate's duality theorem of Galois cohomologies of local fields, allowing the coefficients to be sheaves for the flat topology attached to arbitrary artinian commutative group schemes. In another Annals of Math. paper he proved that cohomological dimension of any non-perfect field of positive characteristic is infinite, a surprise, and also that the coefficient sheaves which caused troubles cannot be commutative group schemes of finite type over the given field.

In the middle 1970s his research direction made a slight turn, from arithmetic to algebraic geometry. In an influential paper he constructed a natural filtration for vector bundles on smooth projective varieties, generalizing the construction of Harder-Narasimhan for vector bundles on projective smooth algebraic curves. He also showed in an algebraic family of vector bundles, the convex polygon which encodes the discrete invariant attached to the filtration he constructed, always rises under specialization. This polygon defines a family of subvarieties on moduli spaces of vector bundles, commonly called Shatz filtration in honor of his contribution.

His charming book "Profinite groups, arithmetic, and geometry", published in 1972, is a stimulating introduction to arithmetic geometry. Based on a spring 1968 graduate course taught at Penn, it goes beyond the standard topics in Galois cohomology and local class field theory, to include topics such as Shafarevich's counter-example to the class field tower problem, Ax's counter-example to Artin's conjecture on forms and cohomological dimension, and (of course) duality theorems for finite commutative group schemes over local fields.

His career took him to conferences around the world, including Moscow in the 1960s and Bonn, Germany, as late as the 2000s. He was a visiting professor at the University of Pisa in Italy from 1966 to 1967, a member of the Mathematical Sciences Research Institute (now the Simons Laufer Mathematical Sciences Institute) in Berkeley, California, from 1986 to 1987, and a member of the Institute for Advanced Study in Princeton, New Jersey, in 1997.

A longtime member of the American Mathematical Society, Steve served as editor of the Transactions of the Society, on the Society’s Council, and on its Executive Committee of the Council. He is the author of numerous works in mathematics, including Profinite Groups, Arithmetic, and Geometry (Volume 67, Annals of Mathematical Studies, Princeton University Press, 1972), and a variety of journal articles.

In lieu of flowers, please make any donations in his honor to the Philadelphia Chamber Music Society.

Mihai (known as Michael in the USA) Pimsner was a Romanian born mathematician known for his work in the K-Theory of Operator Algebras.  He was born in Wallachia (part of Romania) in 1953 and was educated in Romania receiving his Ph.D. from INCREST in Bucharest in 1984.  After occupying a tenured position in Germany, he accepted an invitation to join the Penn Faculty arriving at Penn in 1991, and his presence further strenghtened the research group in functional analysis/operator algebras in the mathematics department.  He was internationally known for his contributions to K-theory, having participated as an invited speaker at one of the quadrennial International Congresses of Mathematicians and he was an Honorary member of the Mathematics Institute of the Romanian Academy of Sciences.

A modest but gifted man who spoke at least three languages fluently, he had a warm ingratiating smile and personality--quiet but effective and he was loved by his students to whom he was exceptionally kind.  All his colleagues enjoyed their interactions with him and will miss him and the steady, reasoned part he played in the department.  He fought a long battle with lung cancer with a blessed lenghty remission, but the disease returned and he died on July 17, 2022.   At his death he left his daughter, Ingrid, and his granddaughter, Sybill.

Richard V. ("Dick") Kadison passed away after a short illness on August 22, 2018.  He was born in New York City on July 25, 1925, attended the Bronx High School of Science, the City College of New York and the University of Chicago (Ph.D. 1950).  During World War II, he was a lieutenant in the US Navy.

After Chicago, he was for many years a senior member of Columbia University's Mathematics Department and was attracted to Penn in 1964 as part of the mid-sixties modernization and build-up of Penn's Mathematics Department undertaken by the then Provost David Goddard and the then Chairman Oscar Goldman.  Indeed, Provost Goddard gave up his own chair (the Gustave C. Kuemmerle Chair) to help attract Kadison to Penn.  Dick held the Kuemmerle chair for the rest of his life.

At Penn, he was instrumental in  building a world famous group in his own area of mathematics (functional analysis and operator theory); in the seventies, this was a great attraction for people to visit Penn's Math Department.  The area of operator theory is not only pure mathematics, it has deep connections to quantum mechanics and quantum field theory, to probability theory as well as to other areas of mathematics.  Dick worked tirelessly at the subject and its applications, he was known world-wide; he was an international mathematician.

During his life, he received many honors.  Among these are the Steele Prize for Lifetime Achievement from the American Mathematical Society (1999), election to the National Academy of Sciences (1996), honorary doctor's degrees from the Universite' Aix-Marseille (1986) and the University of Copenhagen (1987), Foreign Member, Royal Danish Academy of Sciences and Letters (1974), and, a few months before his passing, election to the American Academy of Arts and Sciences (2018).

He leaves Karen, his wife of more than sixty years, and son Lars and his wife, Marit.

James Michael Gardener Fell, known to all who knew him as Michael, died December 16, 2016.  He was a Canadian born (December 4, 1923) but American mathematician, born and raised in Vancouver, BC.  After elementary schooling in Vancouver, he went to England and studied at Eton and would have remained to study at Oxbridge but for the onset of WW II.  So, he returned to the University of British Columbia as undergraduate then was a graduate student at Berkeley where he received the Ph. D. in 1951.

He was an expert in group representation theory and operator algebras and his position before Penn was as a senior member of the University of Washington's Mathematics  Department in Seattle.  Attracted to Penn in 1965 as part of the Mathematics Department's rebuilding (started by Provost Goddard and Chairman Goldman), he was part of the outstanding group in functional analysis then formed in that rebuilding.

Besides his mathematics, he had a passionate interest in languages, speaking fluent Russian and French and, later in life, becoming fluent in Icelandic.  A quiet, but very friendly man, he was known in his family as "Puzzle"--this nickname bestowed upon him by his daughter, Rachel.  When he took Emeritus status in 1991, he embarked on a second career:  that of  scholar in Icelandic and historian of Christianity in Iceland.  He published six books in this latter career, five of them as the first translations into English of old Icelandic religious texts.

He leaves his wife of many years, Daphne, and two children: daughter Rachel and son Peter.

David Shale, Professor Emeritus, died on January 7, 2016.  He was born in New Zealand on March 22, 1932 and was educated there both in school and as an undergraduate.  He then attended the University of Chicago as a graduate student in Mathematics (Ph. D. 1960).  After Chicago, he was an assistant professor at Berkeley and then was attracted to Penn's Mathematics Department in 1964 as  part of the modernization and rebuilding of the Department undertaken by then Provost Goddard and then Chairman Oscar Goldman.  At Penn, he was renowned for his rigorous training of undergraduates which resulted in  very strong performance results from his students and he served two terms as Undergraduate Chair with distinction.

He was an expert in the mathematical foundations of Quantum Physics with many very original ideas on the subject.  In addition, he discovered what is now called the Shale-Weil Representation in operator theory.  He was also an expert in Bayesian Probability Theory, especially as it applied to Physics.  As a hobby, he refurbished of his own home (a farmhouse in West Chester) in the colonial Georgian style and was very talented in this endeavor.

Albert Nijenhuis (November 21, 1926-February 13, 2015) was a Dutch-American mathematician who specialized in differential geometry and the theory of deformations in algebra and geometry, and later worked in combinatorics.

His high school studies at the gymnasium in Arnhem were interrupted by the evacuation of Arnhem by the Nazis after the failure of Operation Market Garden by the Allies. He continued his high school mathematical studies by himself on his grandparents

His university studies were carried out at the University of Amsterdam, where he received the degree of Candidaat (equivalent to a Bachelor of Science) in 1947, and a Doctorandus (equivalent to a Masters in Science) in 1950, cum laude. He was a Medewerker (associate) at the Mathematisch Centrum (now the Centrum Wiskunde & Informatica) in Amsterdam 1951-1952. He obtained a Ph. D in mathematics in 1952, cum laude (Theory of the geometric object). His thesis advisor was Jan Arnoldus Schouten.

Albert came to the United States in 1952 as a Fulbright fellow (1952-1953) at Princeton University. He then studied at the Institute for Advanced Study at Princeton 1953-1955, after which he spent a year as an Instructor in mathematics at the University of Chicago. He then moved to the University of Washington in Seattle, first as an Assistant Professor and then a Professor of Mathematics, departing in 1963 for the University of Pennsylvania, where he was a Professor of Mathematics until his retirement in 1987.

He was a Fulbright Professor at the University of Amsterdam in 1963-1964, and a visiting professor at the University of Geneva in 1967-1968, and at Dartmouth College in 1977-1978. He is now a Professor Emeritus of the University of Pennsylvania and an Affiliate Professor at the University of Washington.

In 1958 he was an invited speaker at the International Mathematical Congress in Edinburgh. He was a J.S. Guggenheim Fellow in 1961-1962, again studying at the Institute for Advanced Study. In 1966 he became a correspondent member of the Royal Netherlands Academy of Arts and Sciences] and in 2012 he became a fellow of the American Mathematical Society.

*This was written based on the longer Wikipedia article.

Herbert S. Wilf, an innovative mathematics researcher, teacher, writer, journal editor, and the University of Pennsylvania 

Thomas A. Scott Emeritus Professor of Mathematics, died on Saturday, January 7, 2012 in Wynnewood, Pennsylvania. The cause of death was a progressive neuromuscular disease.

Wilf was the author of six books and more than 160 research articles. From the 1950's, he was a pioneer in the mathematical programming of early computers, beginning with his work at Nuclear Development Associates, which led to his book Mathematical Methods for Digital Computers, written with A. Ralston. From 1959 to 1962, he taught at the University of Illinois. His early work focused on numerical analysis and complex analysis, and led to numerous research papers as well as a textbook, Mathematics for the Physical Sciences.

Wilf taught at the University of Pennsylvania from 1962 until his retirement in 2006. For him, teaching and research were deeply intertwined, and he was recognized throughout his career for exemplary teaching. In 1973 he received the University of Pennsylvania's Christian and Mary Lindback Award for excellence of undergraduate teaching. In 1996 he received the Deborah and Franklin Tepper Haimo Award for distinguished teaching of mathematics, from the Mathematical Association of America.

In the 1960's, Wilf became interested in the newly developing field of combinatorial analysis. He wrote fundamental research papers, forming the foundation of today's work in discrete mathematics with its applications to computer algorithms and its close interconnections with the mathematical fields of algebra and probability theory. He did pathbreaking work with D. Zeilberger of Rutgers University on a theory of computerized proofs for combinatorial identities. For this work they were awarded the Leroy P. Steele Prize of the American Mathematical Society for Seminal Contributions to Research in 1998. Overall, he contributed over 135 papers in combinatorics and wrote four influential books, including generatingfunctionology and A = B, the latter with M. Petkovsek and D. Zeilberger. In 2004 he was awarded the Euler Medal for Lifetime Contributions by the Institute for Combinatorics and its Applications. He supervised 26 Ph.D. students in combinatorics at the University of Pennsylvania.

Wilf was a pioneer advocate of the open electronic publishing of books and journals. Many of his books are available for free download on his web page, www.math.upenn.edu/~wilf which registered an astounding 350,000 downloads last year. Amazing. He co-founded two major journals, The Journal of Algorithms in 1980 with D. Knuth, and The Electronic Journal of Combinatorics in 1994 with N. Calkin. From 1987 to 1992 he also served as Editor-in-chief of The American Mathematical Monthly, a leading journal that aims for expository and readable dissemination of mathematical work for teachers and researchers. Wilf spoke widely at colleges, universities, and mathematics conferences throughout the world. He was an avid amateur pilot, and often flew himself to these occasions in his private plane.

Over his long career, Wilf co-authored research papers with more than 60 mathematicians. His final papers were as influential as his early ones, including "There's plenty of time for evolution" with W. Ewens, which appeared in the Proceedings of the National Academy of Sciences in 2010. Wilf's wit shone through in some of his whimsical paper-titles, such as "The 'Snake Oil' method for proving combinatorial methods," and in his appreciation of articles written about his work such as B. Cipra's "How the Grinch stole mathematics."

Herbert Saul Wilf was born on June 13, 1931 in Philadelphia, the son of Alexander and Bertha Wilf. He received a B.S. in mathematics from the Massachusetts Institute of Technology in 1952, and a Ph.D. in mathematics from Columbia University in 1958. He is survived by his wife of 59 years, Ruth Tumen Wilf, a daughter Susan, two sons David and Peter, and six grandchildren.

Donations to establish an award recognizing outstanding student achievement may be sent to: Herbert S. Wilf Award Fund, Department of Mathematics, University of Pennsylvania, 209 South 33d Street, Philadelphia, PA 19104-6395.

Some comments on Herb Wilf's Work:

• 65th Birthday Tribute [1996]
• AMS Steele Prize Article [1998]
• A tribute to Herb Wilf. By Doron Zeilberger on Herb's 80th Birthday [2011]; To be published in the Proceedings Volume of the W80 conference, edited by Ilias Kotsireas and Eugene Zima.

Professor Norman Oler, a long time member of the Mathematics Department in SAS, died on the morning of November 1, 2011. Born in Sheffield, England in 1929, he, his father and siblings immigrated to Canada and eventually the United States shortly after the Second World War. He was educated at Universities here and in Canada, receiving his Ph.D. in Mathematics in 1957 from McGill University in Montreal under Hans Zassenhaus.

He came to Penn in 1963 from Columbia University and received Emeritus status in 1993. After his retirement, he continued actively teaching in the Mathematics Department for several years. In his mathematics, he was an expert in the Geometry of Numbers and in the allied field of packing and filling problems in Locally Compact Groups.

He was a gifted councilor whose advice both in the Departm

ent and University wide was often sought and this continued even after his retirement. Perhaps his most important role in this sphere was as director of the Penn-Israel Exchange Program--an exchange program for scholars University wide and their counterparts in the State of Israel. He was successful in raising considerable private sums for this program and had the full support of the University Administration as well as the support of the highest levels of the Israeli Government. In particular, he counted among his friends the then Prime Minister (now President) of Israel, Shimon Peres. He was also active in the Jewish Publication Society of America and, in this connection, was received at the White House and met then President Reagan.

In his private life, he was an avid wood worker during the 60's and 70's, especially toward the beautification of his home in Wynnewood. There, he and his former wife Jacqueline were gracious hosts for the occasional parties that followed the visit of colloquium speakers to the Department. He enjoyed singing, was musically trained and was knowledgeable about the world of Opera.

He leaves his son Col. Adam Oler USAF (an attorney) and daughter-in-law, Lt. Col. Kate Oler USAF, his daughter Dr. Allison Oler Szapary (an internist at Penn Health for Women in Radnor) and son-in-law Dr. Philippe Szapary, his brothers Charles and David, his sister Ruth Plotkin and he had two further sisters, the late Leah Oler and the late Frida Oler Warner. He also leaves five grand-children and his long time companion of his later years, Ria Weissel.

Dr. Andrew H. Wallace, professor emeritus of mathematics at Penn and former chair of the mathematics department (1968-71), passed away January 18 in Chania, Crete, Greece. He was 81.

Born and raised in Edinburgh, Scotland, he graduated in 1946 with an MA in mathematics and physics from Edinburgh University. He earned his PhD in mathematics from St. Andrews University in 1949.

After immigrating to the US in 1959, he served as professor and chair of the mathematics department at Indiana University. He then came to Penn in 1965 and stayed until his retirement in 1986.

Colleagues said his mathematical work was mainly concentrated in topology where he produced fundamental results reported on principally in his series of papers entitled “Modifications and Cobounding Manifolds.” Here, he essentially settled in dimensions 5 and higher, the basic open problem regarding these geometric objects, though he did not push his results to an explicit statement of the solution. This was done by an independent method and almost simultaneously by Dr. Stephen Smale, now professor emeritus at the University of California at Berkeley. Dr. Wallace’s work in the topology of three dimensional spaces was groundbreaking and remains frequently cited and used to the present day.

Described as “a soft-spoken and quiet man, he possessed a dry sense of humor and had gifts as a painter and musician. His principal avocation during his time at Penn and in retirement was sailing. He maintained a 35-foot craft and, when he retired, he and a small crew sailed it across the Atlantic and Mediterranean to his new home in Crete.” His friends in the department remember a series of postcards from Bermuda, the Azores, Gibraltar, Majorca, Malta, Athens and Crete documenting this voyage.

Dr. Wallace is survived by his wife Dimitra; daughters, Linda Kipp, Susan George, and Corinne Summers; four grandchildren; two great-grandchildren; a step-daughter, Irene Chilari; and a step-granddaughter, Dimitra Chilari.

Dr. Chung-Tao Yang, emeritus professor of mathematics and former chairman of the department, died September 15, 2005 of cancer. He was 82 years old.

Dr. Yang was born in Pingyang, a small rural village in southeastern China. He graduated at the top of his class in 1946 from Zhejiang University. In the early 1950s he earned his doctorate degree from Tulane.

“In the field of topological transformation groups, Chung-Tao Yang and his longtime collaborator Deane Montgomery of the Institute for Advanced Study in Princeton were regarded by many as the world’s leaders,” said Dr. Herman Gluck, professor of mathematics.

He taught at the University of Illinois and at Nankai Institute in China and in Taiwan. He became a visiting member of the Institute for Advanced Study in Princeton.

In 1956 he joined Penn as an assistant professor of mathematics. Two years later he was promoted to associate professor, and became full professor in 1961. In the 1960s, Dr. Yang helped to raise the level of the mathematics department at Penn to international prominence. In the early 1970s he served as its graduate chairman, and from 1978 to 1983 as its chairman.  He earned emeritus status in 1991.

Dr. Yang was a member of Academia Sinica, the most prominent academic institution in Taiwan. He was instrumental in raising funds for a mathematics institute at Zhejiang University.

Dr. Yang is survived by his wife, Agnes; sons, Deane Yang and Kenneth Chang; daughters, Lynne Hamrick and Jeanne Yang; and seven grandchildren.

Dr. Lajos Pukanszky, an emeritus professor of Mathematics, died on February 15 at the age of 67. He was considered by many to be the world's leading expert on representations of Solvable Lie Groups. Dr. Pukanszky came to the University from UCLA in 1964, as a full professor. He joined the functional analysis group, just forming in the Mathematics Department. That group became, almost at once, the foremost assemblage of functional analysts in the world; Lajos Pukanszky was one of its stars.

Dr. Pukanszky was born in Budapest, Hungary on Nov. 24, 1928. He was educated at the Universities of Debrecen, Budapest and Szeged, receiving his Ph.D. in 1955 at the University of Szeged.

He fled Hungary during the 1956 uprising, arriving at a Yugoslavian refugee camp. His talents were well recognized on this side of the Atlantic. He received a visa and came to the USA in 1957. His career, here, began with an appointment as a Research Associate at an institute in Baltimore. From there, he moved to a position in the Mathematics Department at the University of Maryland. Shortly after that, he accepted a visiting position at Stanford and then a line position at UCLA. He was promoted to tenure a year following that. At that same time, he was happy and proud to become a citizen of the United States.

For more information on his mathemical contributions, see Pukanszky Obituary in the Notices of American Math. Society.

Oscar Goldman died on December 17, 1986.  He was New York City born (1925) and bred, having attended the City College of New York before his graduate work in Mathematics at Princeton (Ph. D. 1948). Then he was for three years a Benjamin Peirce Instructor at Harvard and subsequently one of the inaugural professors of mathematics at Brandeis. At Brandeis, he (practically) single handedly built up the mathematics department there into a wonderfully strong group beginning from scratch. Because of this, when Provost David Goddard decided (early 60's) that Penn's Mathematics Department needed modernization and rebuilding, he heeded the advice of Murray Gerstenhaber and Chung-Tao Yang (at Penn) and the further advice of his National Academy colleagues Saunders MacLane and Donald Spencer and brought Goldman to Penn to effect the change.

Goldman was extremely successful, partly because he chose wisely in his first senior appointments (and successive junior appointments) in 1963 and 1964 and partly because of the support provided by Goddard. The groups in functional analysis, in geometry-topology and in algebra/number theory gelled quickly and remained the backbone of the rejuvenated department (in addition to joining Gerstenhaber, Yang, Ono and the recently appointed H.S. Wilf). Goldman remained chair until 1967.

As a mathematician, Oscar was first and foremost an algebraist. He had collaborated successfully at Brandeis in several fundamental papers, and continued to produce mathematics at Penn, sometimes in collaboration with his young colleague Chih-Han Sah. A noted quick thinker (and quick wit), he had good intuition besides.

At his death, he left his wife of many years, Madge.

Dock Sang Rim died on November 18, 1982.  He was North Korean by birth (1928), the family fleeing south in the Korean War, and was schooled through college (Seoul National University) in Korea.  He came to the USA as a scholarship fellow at Indiana University for graduate study in Mathematics (Ph. D. 1957).   Then he was at Columbia University and subsequently attracted to Brandeis by its inaugural chairman, Oscar Goldman.  A series of influential papers succeeded therefrom in his Brandeis years, all displaying his characteristic economy of means and power of results.

Oscar Goldman took care to invite and attract Rim to Penn which he joined in 1965.  Quickly, he became and remained a leader and mainstay in the Algebra/Number Theory group and his stamp is obvious when one regards the work done at Penn in these areas in the 70's.  He was Graduate Chair and then Chair of the Department (1975-1978) and provided wise leadership while at the same time being a leader in the Philadelphia Area Korean Community.  He was an Editor of the Transactions of the American Mathematical Society, a post of national election.  He was a member of the Korean Academy of Sciences, whose guest he was in 1982 when he fell ill and died.

In 2021 Dr. Rim was named a 2020 National Laureate in Science and Technology by South Korea. The award was conferred posthumously on April 21, 2021  and attended by the President of the Korean Mathematical Society. With this award Dr. Rim was honored for his contributions to the development of an intellectual exchange between South Korea and the United States in the field of mathematics. In addition, Dr. Rim was the first Korean mathematics professor in the Ivy League. His research at Penn laid the cornerstone of algebraic K-theory, including pioneering studies on cohomology.

At his passing, he left his wife, Hihyun, and three children: Tom, Patty and David.